Skin whitening activity

Skin whitening has been in practice around the world with Asia as the largest market. As much Asian female preferred more fair skin tone, skin whitening product has become and continues to be the best selling skin care products in Asia (Wang et al., 1997). Tyrosinase inhibition is the most common approach to achieve skin hypo-pigmentation as this enzyme catalyzes the rate-limiting step of pigmentation. Despite the large number of tyrosinase inhibitors in vitro, only a few are able to show induced effects in clinical trials. In this chapter, we review some potential marine organisms with its effects on pigmentation of skin focusing mainly on tyrosi-nase inhibitors. Hence, development of novel tyrosinase inhibitors from natural resources continues to arouse great attention, and in recent years, marine algae have attracted great attention in the search of natural tyrosi-nase inhibitor agents (Solano et al., 2006).

Recently, Cha et al. investigated 43 indigenous marine algae for tyrosinase inhibiting activity (Cha et al., 2010). They reported that extracts from Ecklonia cava and Sargassum silquastrum exhibited excellent inhibitory effects on the pigmentation of zebra fish, which is due to their potential tyrosinase inhibitory activity. Fucoxanthin isolated from Laminaria japonica has been reported to suppress tyrosinase activity in UVB-irradiated guinea pig and melanogenesis in UVB-irradiated mice. Oral treatment of fucoxanthin significantly suppressed skin mRNA expression related to melanogenesis, suggesting that fucoxanthin negatively regulated melano-genesis factor at transcriptional level (Shimoda et al., 2010). Fucoxanthin and astaxanthin have been demonstrated to possess photoprotective properties in human fibroblast cells via inhibition of DNA damage and enhance antioxidant activity (Heo and Jeon, 2009). Further, potential whitening effects of diphlorethohydroxycarmalol isolated from Ishige okamurae have been reported (Heo et al., 2009a, 2010). Phloroglucinol derivatives, a common secondary metabolite constituents of brown algae, possess tyrosinase inhibitory activity due to its ability to chelate copper in this enzyme (Kang et al., 2004). Some phlorotannins such as 7-phloroeckol and dioxinodehydroeckol have been described to inhibit tyrosinase activity stronger than arbutin and kojic acids (Yoon et al., 2009). Flavonoid glycoside derived from Hizikia fusiformis has been reported as potential tyrosinase inhibitor. H. fusiformis is one of the most common edible brown macroalgae belonging to the Sargassaceae family (Ranathunga et al., 2006).

These evidences suggest that bioactive compounds derived from marine algae have a promising potential to be used as skin whitening agents. There are numerous advantages of marine algae, such as relatively low production costs, broad spectrum of skin whitening properties, low cytotoxicity, safety, wide acceptability, and novel modes of action, suggesting marine algae as nutritious food which can be used to restore female beauty; however, further studies are needed with clinical trials for their whitening effects.